The present invention relates to a semiconductor device which has a film having high reflectance deposited under an insulating film.
Conventionally, as shown in FIG. 2, in order to make a contact hole on an insulating film 2 formed on a film 1 having high reflectance, a photoresist 4 is applied on the insulating film 2, a thin mask pattern 5 is photolithographed on the photoresist 4 by photolithography technology using a photomask 6 to pattern the photoresist 4, and then the insulating film 2 is etched by using the photoresist patterned 4 as a mask.
In the above method, when the photoresist 4 on the insulating film 2 is patterned by photolithography technology, an exposure light 7 penetrates the photoresist 4 and the insulating film 2 and is reflected by the film 1 having high reflectance under the insulating film 2. A light 8 reflected by the film 1 having high reflectance exposes a part of the photoresist 4 that should not be originally exposed, which results in the formation of a pattern of the photoresist 4 that does not correspond to the pattern of the photomask 6 used to pattern the photoresist 4.